This is where it begins. This outer slug is what will hold your TWIST thumb. Drill a 1 1/2" hole the depth of the out slug. Clean out the hole, scuff up the outer for proper adhesion, line up the vertical groove to 6 o'clock on your grip center line and install.
Want to use the JoPo Grips system but want to use your own thumbs? This inner sleeve will let you put your own 1 1/4" slug inside of it. Glue your slug in the sleeve then TWIST into the outer.
This is the JoPo Grips inner sleeve w/ slug already installed. Set your outer sleeve, using the TWIST tool, lock in this inner sleeve w/ slug and drill your thumb as you like. Once you have a few thumbs, just stock up on outers!